<?php
$captcha = $this->captcha;
$txtCaptcha = $this->formText('captcha', '');
$txtID = $this->formHidden('captchaID' , $this->captcha_id);
?>
<form action="" method="post">
    <?php echo $captcha;?>
    <br>
    Nhập captcha: <?php echo $txtCaptcha . $txtID;?>
    <input type="submit" />
</form>